Any even specially treated surfaces of electrical contacts are not perfect in shape. This fact is caused by deviations of different kind and different scale. They are typically classified into [1] subroughness, roughness, waviness (quasi-periodic deviations) and macro deviations (single technological surface defects). These lead to fragmentation of contact spots: but a part of contact surface is conductive. Fragmentation causes the potential and the current density distributions to be distorted in the contact vicinity. It can change the magnitude of the contact resistance and affect the dynamics of the heating when the current passes through contacts. In this work, we analyzed the effect of fragmentation on the high-current contact heating when shock short-circuit currents pass through them. We used numerical calculations performed in ANSYS to assess the impact of macro deviations and waviness on the temperature change in contacts. The effect of material softening and associated changes in the surface profile on parameters of electrical contacts was also evaluated. The results are compared with the data of similar calculations performed in the approximation of fully conductive contact spots [2].